Back support for a chair

ABSTRACT

There is described a back support for a chair. The back support comprises a body for receiving a back of a user when the user is in a seated position on said chair. The body has one or more shape adaptive members capable of adapting their shape in response to pressure applied by the back of the user when the user is in a said seated position. The one or more shape adaptive members are positioned proximal the user&#39;s vertebral column when the user is in the seated position.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application claims priority from Australian Provisional Patent Application No 2005905152 filed on 16 Sep. 2005, the content of which is incorporated herein by reference.

FIELD OF THE INVENTION

The present invention relates to a chair and in particular to a back support for a chair which provides adjustable support to the vertebral column of a seated individual.

BACKGROUND ART

In modern society, people spend an increasing amount of time in a seated position. In most office environments and workplaces, more and more people are being employed in positions where their daily duties are desk orientated and they spend the majority of their day seated at their own workstation. Further, with the popularity of television and video games and the like, many individuals are also spending a great deal of their leisure time in a seated position.

Given such a large amount of time spent by individuals in a seated position, it is important that they are provided with chairs that are comfortable and provide sufficient support to ensure correct posture as well as to reduce stress on the individual's back and prevent any back related problems from developing. In this regard, one of the most important features of any chair is in the manner in which the chair supports the user's back. Should a chair provide inadequate support, or support the back in an improper position, the user may become uncomfortable after sitting for a prolonged period of time. This can in turn contribute to chronic back problems, which can easily be avoided through correct back support.

The human back differs in size, shape and strength from individual to individual, and as a result the ideal type of back support will also differ from individual to individual. Unfortunately, most available chairs are typically designed with the back support sized and shaped to accommodate an average person having an average build, and hence do not suit all individuals. In this regard, most office type chairs are provided with various adjustment mechanisms to adjust the height and position of a variety of features of the chair, such as back support angle and height, however whilst this allows a variety of different configurations of the chair, they are typically limited in range and not always adjusted according to the correct postural needs of the individual.

In this regard, there is a need to provide a chair which employs a back support that is readily conformable to the back of a variety of individuals to support the individual's spine in a manner which optimises weight distribution and/or which cradles the back to reduce pressures being transferred to the user's spine.

Any discussion of documents, acts, materials, devices, articles or the like which has been included in the present specification is solely for the purpose of providing a context for the present invention. It is not to be taken as an admission that any or all of these matters form part of the prior art base or were common general knowledge in the field relevant to the present invention as it existed before the priority date of each claim of this application.

SUMMARY OF THE INVENTION

Throughout this specification the word “comprise”, or variations such as “comprises” or “comprising”, will be understood to imply the inclusion of a stated element, integer or step, or group of elements, integers or steps, but not the exclusion of any other element, integer or step, or group of elements, integers or steps.

In a first aspect, the present invention is a back support for a chair, comprising:

a body for receiving a back of a user when said user is in a seated position on said chair; and

one or more shape adaptive members attachable to said body wherein the shape of the or each shape adaptive member is variable in response to pressure applied thereto by the back of said user when said user is in said seated position; wherein, the one or more shape adaptive members are arranged proximal said user's vertebral column when the user is in said seated position.

In one embodiment of this aspect, the body is a substantially vertical body having a support surface against which at least a portion of the user's back is received. A portion of the body proximal said support surface may be provided with a soft and flexible material, such as foam, to provide comfort to the user. In one form, the support surface may be a substantially flat surface. In another form, the support surface may be contoured to conform to the user's back.

The one or more shape adaptive members may be in the form of a pouch containing a quantity of gel material. The gel material may be a hydrogel or a polymer gel. In one form, the gel material may be a viscoelastic polyurethane gel. The pouch containing the gel material may be a polyurethane film material which assumes the shape of the gel material contained therein. In this regard, the shape of the pouch may readily change in response to pressure applied thereto by the back of the user. Such pressure causes a change in the distribution of the gel within the pouch. The pouch may be in the form of an elongate strip of gel material.

In one embodiment, one shape adaptive member may be positioned on the support surface of the body. In this regard, the shape adaptive member may extend along the support surface for substantially the height of the body. The shape adaptive member may be positioned such that it extends centrally along the support surface of the body to be positioned adjacent the vertebral column of the user when in said seated position. In this regard, the body may be formed with a recess provided therein for receiving the shape adaptive member. The shape adaptive member may be attached within the recess by way of an adhesive or the like.

In this embodiment, the shape adaptive member may be positioned to receive the vertebral column of the user and to adapt to the shape of the region of the user's back, adjacent the vertebral column. Such an arrangement may optimise the weight and pressure distribution between adjacent vertebrae of the vertebral column.

In another embodiment, two shape adaptive members may be positioned on the support surface of the body. In this regard, the shape adaptive members may extend along the support surface for substantially the height of the body. The shape adaptive members may be positioned such that they extend centrally along the support surface of the body to be positioned adjacent the vertebral column of the user when in said seated position. In this regard, shape adaptive members may be separated by a gap having a distance of between 25-75 mm. The gap may be recessed from the surface of the shape adaptive members defining an open space between the shape adaptive members. Each shape adaptive member may have a width of between 25-75 mm. The body may be formed with a pair of recesses provided therein for receiving the shape adaptive members. The shape adaptive members may be attached within the recesses by way of an adhesive or the like.

In this embodiment, the shape adaptive members may be positioned to receive the region of the user's back proximal the transverse processes of the vertical column, such that the spinous process may extend into the gap provided between the shape adaptive members. The shape adaptive members may adapt to the shape of the region of the user's back, adjacent the transverse processes of the vertebral column, to optimises the weight and pressure distribution between adjacent vertebrae of the vertebral column.

In another embodiment, the one or more shape adaptive members may be attached to the body such that they are substantially flush with the support surface of the body. In yet another embodiment, the shape adaptive members may be attached to the body such that they at least partially project beyond the support surface of the body.

In a second aspect, the present invention is a chair comprising:

a base;

a seat supported on said base; and

a back support attachable to said base and extending substantially vertically therefrom, said back support comprising:

a body for receiving a back of a user when said user is seated on said seat and one or more shape adaptive members attachable to said body, wherein the shape of the or each shape adaptive member is variable in response to pressure applied thereto by the back of said user when said user is seated on said seat; wherein, the one or more shape adaptive members are arranged proximal said user's vertebral column when the user is seated on said seat.

BRIEF DESCRIPTION OF THE DRAWINGS

By way of example only, the invention is now described with reference to the accompanying drawings:

FIG. 1 is a perspective view of a chair incorporating one embodiment of the present invention;

FIG. 2 is a front view of a chair incorporating a second embodiment of the present invention;

FIG. 3 is a top cross sectional view of the back support of the chair of FIG. 1; and

FIG. 4 is a top cross-sectional view of the back support of the chair of FIG. 2.

DETAILED DESCRIPTION OF AN EXEMPLARY EMBODIMENT OF THE PRESENT INVENTION

A chair incorporating the back support of the present invention is generally shown in the accompanying drawings as 10. Whilst the present invention will be described in relation to a standard office chair 10, it will be appreciated by those skilled in the art that the shape and type of the chair 10 could be any desired shape and type as desired.

As shown in FIGS. 1 and 2, the chair 10 generally comprises a base 12, a seat portion 14, arm rests 16 and a back support 18. The chair 10 is provided to accommodate a user in a sitting position with their posterior supported on the seat portion 14 such that the user's feet are able to be positioned on the ground which supports the base 12 of the chair 10.

Whilst the base portion 12 has been shown as incorporating wheels or castors 11 to enable the chair to be movable across a support surface, it will be appreciated that the chair 10 could incorporate standard legs having stopper elements or the like provided thereon, to prevent movement/slippage of the chair 10 across the support surface. Similarly, whilst arm rests 16 are shown, it will be appreciated that the present invention could be equally applied to a chair 10 without arm rests 16.

The seat portion 14 comprises a cushion which receives the posterior of the user and provides comfort and support to the user to maintain a substantially upright seating posture. The seat portion 14 can be configured in a number of ways and may be adjustable such that it can slope forward to ensure that the user is positioned with a straight back, and can be raised and lowered, by way of a handle 15 (FIG. 2), to accommodate users of variable heights and sizes.

As described in the Applicant's Registered Australian Patent 747131, which is incorporated herein by reference, the seat portion 14 may have more than one cushion provided thereon. In this regard, a forward and a rearward cushion may be provided, with the rearward cushion having a higher resistance to resilient deformation than the forward cushion, or vice versa, to provide the desired amount and type of back alignment.

The cushion(s) of the seat portion 14 may be made from a foam material, in the form of cut or moulded foam. The foam material can be a rubber latex foam and/or a polyurethane foam comprising a network of cellular shapes, thereby increasing the resilient flexibility of the seat portion 14. Similarly, the cushion(s) of the seat portion 14 may be layered with a variety of materials, such as foams and/or gel material to provide the desired support to the pelvis of the user and to ensure that the user is positioned upon the chair in a comfortable manner which ensures correct posture.

The back support 18 of the chair 10 extends upwardly from the rearward edge of the seat portion 14, as is shown in FIGS. 1 and 2. The back support 18 may be adjustable in both a vertical and lateral direction in accordance with the needs of the individual user.

The back support 18 forms a flat or contoured support surface 20 which is provided to gently cradle the back of the user seated in the chair 10. In this regard, the back support 18 comprises a frame portion 22, in the form of a rear shell or internal skeleton which provides the general shape/structure of the back support 18. Provided within and/or about the frame portion 22 is a foam material 24, shown more clearly in FIGS. 3 and 4.

The foam material 24 forms the majority of the support surface 20 of the back support 18 and may be a rubber latex foam or a polyurethane foam which is cut or moulded to form the desired surface contour. Typically this contour is slightly concave such that the surface 20 is able to gently cradle the back of the user. The foam material 24 is flexible to provide comfort to the user and may have a variable density and firmness depending upon the desired requirements of the user. A cover 21 in the form of a fabric covering may be provided to surround the foam material 24 before being mounted to the fame portion 22.

The foam material 24 may be Dunlop Enduro®—EN36-100 or Dunlop Enduro®—EN36-130 which has a resistance to resilient deformation of about 80-95 Newtons. However other types of foams are also envisaged to be used in concert with the present invention.

As shown in FIGS. 1 and 2, a shape adaptive member in the form of a spinal support 25 is provided to receive and support the vertebral column of the user seated in the chair 10. The spinal support 25 extends substantially the height of the back support 18 in a central region which corresponds to the vertebral column of the user when seated in the chair. Whilst the spinal support 25 is shown as extending the entire height of the back support 18, it will be appreciated that the support 25 could extend along only a portion of the height of the back support 18 as necessary to provide sufficient support to the vertebral column of the user.

As shown in FIGS. 1 and 3, in one form the spinal support 25 is a shape adaptive flexible pouch 30 provided in a single strip that extends along the central region of the back support 18. The flexible pouch 30 contains a gel material within a suitable protective layer which forms a relatively soft and conformable surface for receiving and supporting the spine of the user. The gel material may be a hydrogel or a polymer gel, such as a viscoelastic polyurethane gel. Such a gel is sold under the trademark “ISOGEL” by Pittsburgh Plastics Manufacturing, Inc. of Zelienople, Pa., United States of America. The protective outer layer can comprise a polyurethane film material.

As shown in FIG. 3, the pouch 30 is positioned atop the foam material 24 and has a width of between 50-100 mm. In this regard, the foam material is moulded to define a space for receiving the pouch 30 which is secured within the space by way of an adhesive material or the like. In this arrangement, the outer surface of the pouch 30 is substantially flush with the surface 30 of the back support 18 to define a surface that is capable of readily adapting to the shape of the person's spine, thereby adjusting to the ongoing needs of the spine and providing optimal weight and pressure distribution from the spine against the back support 18 of the chair 10. In this regard, the pouch 30 simulates body fat tissue and cradles the back to minimise lordosis of the spine.

As is appreciated, the vertebral column of an individual is composed of a series of thirty-one separate bones known as vertebrae 35. There are seven cervical or neck vertebrae, twelve thoracic vertebrae, and five lumbar vertebrae. Each vertebrae 35, as represented diagrammatically in FIGS. 3 and 4, comprises an anterior body 36 and a posterior arch 37. The arch 37 encloses an opening 38 which forms a canal in which the spinal cord is housed. The arch 37 comprises three bony elements, namely the spinous process 39 which extends from the posterior of the arch 37, and a pair of transverse processes 40 which extend laterally from the arch 37. These bony elements serve as important sites of attachment of deep back muscles and also serve as important protective means for protecting the spinal cord.

Whilst not shown, adjacent vertebrae in the vertebral column are connected by specialised cartilaginous joints known as invertebral discs. Each disc is composed of a central core of gelatinous material and a surrounding series of fibrous rings. Body weight of an individual is transmitted through the disc by loading the gelatinous material, which then compresses and transfers its loading to the fibrous rings of the disc. In most individuals, the fibres of the fibrous discs resist this load, but in some instances they may not, resulting in the gelatinous material being forced out of the disc, and the disc becoming herniated/ruptured, which can have a profound effect on the adjacent spinal nerve.

In this regard, by providing a pouch 30 of gel material in the region of the back support 18 of the chair 10 that receives the vertebral column such that the spinous process 39 and the transverse processes 40 are accommodated, the chair 10 is able to better assist in distributing the weight and pressure experienced between the vertebrae 35.

FIGS. 2 and 4, show another embodiment of the shape adaptive members 25 of the present invention. In this embodiment, the shape adaptive member/spinal support 25 is also shown as extending the height of the back support 18 of the chair 10, however it will be appreciated that the spinal support 25 could extend only a portion of the height of the back support 18 as required.

In this embodiment, a pair of shape adaptive members or pouches 32 are provided in the form of strips which extend centrally along the back support 18 of the chair 10 atop the foam material 24. The foam material 24 is moulded/shaped to receive the pouches 32 in the manner as shown in FIG. 4. The pouches 32 are made from the same materials as the pouch 30 discussed above, and provide malleable surfaces which are able to conform to the back of the user in the manner as discussed above.

Each of the pouches 32 are separated by a distance of between 25-75 mm and have a width of between 25-75 mm. The foam material 24 provided in the gap between the pouches 32 is recessed from the outer surface of the pouches 32 to provide a recess 33.

As shown in FIG. 4, in such an arrangement, the pouches 32 act to support the transverse processes 40 such that the spinous process 39 is received within the recess 33. This arrangement provides maximum weight/pressure distribution between the vertebrae if the vertebral column providing additional comfort and support to the user.

It will be appreciated that by providing a chair 10 having such a spinal support 25 formed therein increases spinal stability of the user of the chair. Such a chair 10 is particularly useful for users suffering from back related problems, such as ruptured or herniated discs and ensures that weight is evenly distributed against the chair.

It will be appreciated by persons skilled in the art that numerous variations and/or modifications may be made to the invention as shown in the specific embodiments without departing from the spirit or scope of the invention as broadly described. The present embodiments are, therefore, to be considered in all respects as illustrative and not restrictive. 

1. A back support for a chair, comprising: a body for receiving a back of a user when said user is in a seated position on said chair; and one or more shape adaptive members attachable to said body; wherein the shape of the or each shape adaptive member is variable in response to pressure applied thereto by the back of said user when said user is in said seated position; wherein, the one or more shape adaptive members are arranged proximal said user's vertebral column when the user is in said seated position.
 2. A back support according to claim 1, wherein the body is a substantially vertical body having a support surface against which the user's back is received.
 3. A back support according to claim 2, wherein the support surface is a substantially flat surface.
 4. A back support according to claim 2, wherein the support surface is contoured to conform to the user's back.
 5. A back support member according to claim 2, wherein a portion of the body proximal the support surface is provided with a soft and flexible material.
 6. A back support member according to claim 2, wherein said one or more shape adaptive members are located proximal said support surface.
 7. A back support member according to claim 6, wherein the one or more shape adaptive members comprise a pouch containing a quantity of gel material.
 8. A back support member according to claim 7, wherein the gel material is a hydrogel or a polymer gel.
 9. A back support member according to claim 8, wherein the gel material is a viscoelastic polyurethane gel.
 10. A back support member according to claim 7, wherein the pouch is constructed from a polyurethane film material which assumes the shape of the gel material contained therein.
 11. A back support member according to claim 10, wherein the shape of the pouch changes in response to pressure applied thereto by the back of the user, which causes a change in the distribution of the gel within the pouch.
 12. A back support member according to claim 7, wherein the pouch is an elongated strip.
 13. A back support member according to claim 7, wherein the or each pouch is positioned on the support surface of the body.
 14. A back support member according to claim 13, wherein the or each pouch extends along the support surface for substantially the height of the body.
 15. A back support member according to claim 14, wherein the or each pouch extends centrally along the support surface of the body to be positioned adjacent the vertebral column of the user when said user is in said seated position.
 16. A back support member according to claim 2, wherein the body has one or more recesses formed therein for receiving the one or more shape adaptive members.
 17. A back support member according to claim 16, wherein the one or more shape adaptive members are attachable within the one or more recesses by way of an adhesive.
 18. A back support member according to claim 7, wherein two shape adaptive members are positioned on the support surface of the body.
 19. A back support member according to claim 18, wherein each shape adaptive member extends along the support surface for substantially the height of the body.
 20. A back support member according to claim 19, wherein each shape adaptive member extends centrally along the support surface of the body to be positioned adjacent the vertebral column of the user when said user is in said seated position.
 21. A back support member according to claim 20, wherein the shape adaptive members are separated by a gap.
 22. A back support member according to claim 21, wherein the gap is recessed from an outer surface of the shape adaptive members to define an open space between the shape adaptive members.
 23. A back support member according to claim 22, wherein the open space between the shape adaptive members receives the region of the user's back proximal the spinous process of the user's vertebral column when said user is in said seated position.
 24. A back support member according to claim 21, wherein each shape adaptive member may have a width of between 25-75 mm.
 25. A back support member according to claim 24, wherein the shape adaptive members are positioned to receive the region of the user's back proximal the transverse processes of the user's vertebral column when said user in said seated position.
 26. A back support member according to claim 17, wherein the one or more shape adaptive members are attached to the body such that they are substantially flush with the support surface of the body.
 27. A back support member according to claim 17, wherein the one or more shape adaptive members are attachable to the body such that they at least partially project beyond the support surface of the body.
 28. A chair comprising: a base; a seat supported on said base; and a back support attachable to said base and extending substantially vertically therefrom, said back support comprising: a body for receiving a back of a user when said user is seated on said seat and one or more shape adaptive members attachable to said body, wherein the shape of the or each shape adaptive member is variable in response to pressure applied thereto by the back of said user when said user is seated on said seat; wherein, the one or more shape adaptive members are arranged proximal said user's vertebral column when the user is seated on said seat. 